A night drive over the Afsluitdijk in heavy snowfall, visibility roughly 30 metres. An hour later, further on near Assen, the snow has turned into pouring rain, visibility roughly 35 metres. What is correct?
In both cases the rear fog light may be on, because visibility is below 50 metres in both
During the snowfall the rear fog light may be on, during the rain it may not
In neither case may the rear fog light be on, because the weather cause does not count
Explanation
False — trap: rain-and-fog confused. The visibility figure alone is not enough; the cause must be fog or snowfall. In rain the rear fog light stays off, even below 50 m (Book p.191).